The electrical automobile is currently under intense development due to the twin needs to reduce air pollution and conserve fuel resources.
One of the major difficulties in the development of the electrical automobile is supplying the power for the electrical drive motors. Such power is currently furnished by batteries. Present battery technology, however, is not capable of providing the energy needed to run the automobile over extended distances.
In addition, the present-day battery systems are usually deficient in providing the majority of the other major requirements for vehicles. Automotive batteries should be inexpensive and possess long shelf lives, light weight and short recharge times. Most batteries will provide some, but not all, of these needs.
Many of the aforementioned battery design guidelines compete with each other, so that maximizing one requirement often negatively influences another requisite of design. The several competing specifications associated with vehicular battery technology have caused many to doubt whether an electrical automobile using battery power can ever realistically be a practical form of transportation in the near future.
Some have suggested replacing stored electrical power with a hybrid vehicle system. Such hybrid systems are designed to provide electrical power with small gasoline engines that drive dynamos, which, in turn, power the electrical motors. The value of these hybrid systems is that small engines consume fuel at a much lower rate, and are ultimately less polluting, than vehicles having standard gasoline or diesel engines.
Others have suggested that hybrid vehicles only add to the complexity of vehicular design, thus increasing costs, as well as posing problems with repair and maintenance. Even advocates of these systems admit that this is not the ultimate answer; they suggest that hybrid systems combining batteries with heat engines are an interim measure in the development of truly electrical automobiles and, as such, might not merit the development costs therefor.
Other fuel-cell systems that do not store hydrogen, but rather generate it in situ can, likewise, be unsafe and impractical. Using certain hydrogen-containing chemicals can be dangerous; they are also generally expensive, as well as heavy. Utilizing metal hydrides can be expensive, particularly those that are easily reversible, because they are also easily poisoned by air and moisture that can leak into the system.
An old, now abandoned method of hydrogen generation, i.e., generating hydrogen by passing high-temperature steam over a bed of iron, can also be too expensive and impractical. The containers needed to generate and handle the high-temperature steam are too expensive. Further, the use of high-temperature steam can be dangerous.
The present invention entails the development of a new hydrogen-air fuel-cell system utilizing a new form of reactive iron to generate the hydrogen needed for the hydrogen-oxygen reaction.
The iron of this invention is uniquely comprised of freshly ground particles that increase the reactivity of the iron, so that it is able to react rapidly in a water/iron or steam/iron reaction at a lower-than-normal temperature.
The iron particles are ground when the vehicle is initially powered and throughout vehicular operation. The instantaneous grinding of the iron particles in situ is necessitated because iron becomes rapidly oxidized after grinding. (As early as fifteen minutes after grinding, iron will lose its enhanced reactivity.) Therefore, after the initial grinding, grinding should continue onboard the vehicle or, alternatively, by periodically injecting freshly-ground iron fuel charges from sealed packets.
The inventive iron produces hydrogen at safer and more practical water or steam temperatures than heretofore achieved; it then supplies the hydrogen to the fuel cell for immediate consumption. When fed to the fuel cell, the generated hydrogen will react with the oxygen from the air. This fuel cell reaction will generate the needed electricity to power the drive motors of the vehicle, as well as provide at least some of the replacement water needed to produce subsequent hydrogen from the iron bed.
This inventive method is a cost-effective hydrogen generation scheme, since the lower-than-normal temperature of the water or steam reaction does not require large amounts of energy input to initiate the reaction, nor are complex and costly piping needed in order to convey the fluids.
The freshly-ground, reactive iron is easily deposited in a compartment in the vehicle. The iron is easily handled as sealed packet(s) of freshly-ground particulates, but it can, additionally, be freshly ground in situ aboard the vehicle. The particles range in diameter size from approximately 25 to 1,200 .mu.m; an average-sized distribution is one in which at least twenty per cent (20%) of the particles are less than 300 .mu.m in diameter. It is preferable that at least 50% are less than 300 .mu.m in diameter. The average particle density ranges approximately from about 1 to 7.8 g/cc, with a non-compressed packed particle density ranging from about 1.5 to 3 g/cc. The particles have a surface area greater than approximately 0.001 meters.sup.2 /g.